Apparatus for sorting products



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ATTORNEYS July 15, 1969 P. M, L. SIMMONS I APPARATUS FOR SORTINGPRODUCTS Filed March 9, 1967 6 Sheets-Sheet 2 omm-mmmmm o $53 INVENTOR.PATRICK M. L.S|MMONS ATTORNEYS July 15, 1969 P. M. L. SIMMONS APPARATUSFOR SORTING PRODUCTS 6 Sheets-Sheet 5 INVENTOR. PATRICK M.L.SIMMONS BYM0 Filed March 9, 1967 370? @1417 TO LINE I8IA,F|G.6A ATToRNEYs 36a 5 TOLINE 6|, FIG.5A

July 15, 1969 P. M. L. SIMMONS 3,455,444

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lNVE'NTOR. PATRICK M.L.SIMMONS FIG. 6A 9914 ATTORNEYS United StatesPatent Ofice 3,455,444 Patented July 15, 1969 US. Cl. 209-82 9 ClaimsABSTRACT OF THE DISCLOSURE An apparatus for sorting products accordingto their lengths. The product to be sorted is moved at a predeterminedspeed by a conveyor through a scanning zone which employs a light sourceand a light sensitive cell for generating an electric pulse while theproduct is being moved through this scanning zone. The electric pulse isused to control the supplying of pulses from a pulse generator to acounting apparatus which counts the pulses while the product is in thescanning zone, so that the number of pulses counted is a measure of theproduct length. A control signal is supplied to a solenoid controllingan air jet valve whereby this solenoid is energized long enough so thatthe air jet controlled thereby can deflect the product in the sortingoperation.

This invention relates to apparatus for sorting products such ascucumbers according to their lengths.

An object of this invention is to provide an improved apparatus forsorting products according to lengths thereof, said apparatus employinga photodetector device for scanning the product during movement of theproduct thereover, whereby a signal is produced to gate the output of apulse generator to supply pulses from the generator to pulse responsivemeans such as a counting means which provides output signalscharacterized by the length of the products which are to be sorted.

Another object of this invention is to provide an improved productsorting apparatus for sorting products according to the lengths thereof,said apparatus employing a pulse generator which supplies pulses to acounting means during intervals when the products are moved through ascanning zone, said counting means providing outputs which arecharacterized by the different product lengths so that productdeflecting means for deflecting products of different lengths may beselectively energized and said products sorted according to the lengthsthereof.

Still another object of this invention is to provide an improved sortingapparatus for sorting products according to the length thereof, saidapparatus being provided with an electronic counting means which isactuated while a product is in a scanning zone so that products ofdifferent lengths are characterized by different signals received fromthe counting means.

Other and further objects of this invention will be apparent to thoseskilled in the art to which it relates from the following specification,claims and drawing.

In accordance with this invention there is provided an improvedapparatus for sorting products according to their lengths. In thisapparatus the product to be sorted is moved by suitable conveyor meansthrough a scanning zone which employs a photodetector device. Thisapparatus also employs a pulse generator which is in continuousoperation and generates pulses at a predetermined rate. The output ofthe photodetector is employed to trigger a Schmitt trigger circuit whichsupplies a pulse through suitable amplifying means to a gate that isconnected to control the supplying of pulses from the pulse generator toan electronic pulse counting means. The pulse counting means is providedin two sections, one of which is responsive to the individual pulses andis designated the tenths counter, and the other one of which isresponsive to the output of the first section which furnishes an outputpulse for each ten input pulses. The second section is designated theunits section for reasons which will be apparent further in thedescription of this invention. These sections are provided with lengthselection switches which may be manually adjusted whereby they willprovide output signals at predetermined product lengths, for example,medium lengths and long lengths. At the same time, signals from thephotodetector circuit output are transmitted to another gate. This gatewhich is referred to as the medium length gate is also connected toreceive the medium length signals from the counting means. The outputfrom the medium length gate is supplied to suitable delay circuitsemploying monostable multivibrators for controlling the air delay andair time of the air supplied to the air jet solenoid valve whichcontrols the air to the medium length deflector apparatus for deflectingthe medium length products from their line of travel to suitablereceptacle or conveying means provided therefor. The signals for thelong length products are transmitted to the long length output circuitwhich is supplied to signal delay means employing monostablemultivibrator circuits for providing suitable delay to the solenoidvalve which controls the air jet for deflecting the long products. Thissignal delay is similar to the signal delay employed for the mediumlength signals.

Further details of this invention will be set forth in the followingspecification, claims and drawing in which, briefly:

FIG. 1 is a schematic wiring diagram of an embodiment of this apparatusshowing the control logic unit and the counting and driving means inblock form;

FIG. 2 is a sectional view taken through the length of the conveyorshowing only one of the conveyor belts;

FIG. 3 is an end view showing the conveyor, product scanning apparatusand product deflecting jets;

FIG. 4 is a plan view of a portion of the V-shaped trough conveyoremployed in this apparatus for conveying the products through a scanningzone in which the photodetector is positioned;

FIGS. 5 and 5A show a wiring diagram of the logic unit shown in FIG. 1.FIGS. 5 and 5A should be viewed together with the right hand side ofFIG. 5 joined to the left hand side of FIG. 5A, as shown in the blockdiagram in the upper right hand corner of FIG. 5A;

FIGS. 6 and 6A show the wiring diagram of the counter and driveremployed in each of the counter-driver blocks shown in FIG. 1. FIGS. 6-and 6A should be viewed together with the right hand side of FIG. 6joined to the left hand side of FIG. 6A, as shown in the block diagramin the upper right hand corner of FIG. 6A; and

FIG. 7 is a diagram showing the waveform of input to decade counter overline 45, and also showing the waveforms supplied at output terminals117, 118, 119 and 120 of the decade counter.

Referring to the drawing in detail, reference numeral 10 designates aphotodetector or light-sensitive cell which may be of the infraredsensitive silicone photodiode type. This photodetector is positionedopposite the light source 10a to receive radiant energy therefrom whenno opaque object is interposed therebetween, as shown in FIG. 3. Thelight source 10a produces an output that is rich in the near infraredportion of the spectrum. The photodetector 10 and the light source 10amay be located above and below the conveyors 12 and 13, respectively, asshown in FIGS. 2 and 3. These conveyors are supported on suitablepulleys to form a trough therebetween and they are of the type disclosedin Patent No. 3,212,621.

The articles A, A1 and A2, which are to be sorted according to theirlengths, are supplied to the conveyor 12-13 as a single file fromapparatus such as is disclosed in Patents No. 2,728,443 and No.2,792,929. The articles are spaced on the conveyors 12-13 and moved insingle file to the scanning zone in which the photodetector 110 andlight source a are positioned. When an article A is passing between thephotodetector 10 and the light source 10a, the light rays emitted by thesource 10a are interrupted by the article for a time interval, dependingon the length of the article and the velocity thereof.

The photodetector 10 is connected by lines 14 and 15 to the input of aSchmitt trigger circuit including transistors 17 and 25 shown in FIG. 5.Line 14 is coupled by capacitor 16 to the base of transistor 17. Line 14is also connected by resistor -18 to the positive 15 volt line 19 tosupply electric current to the photodetector. The light source 10a isconnected between the lines 19 and 20. Line 20 is connected to thecollector of transistor 22 through resistor 21. Thus, the light source10a, resistor 21 and transistor 22 are connected in series between thepositive 15 volt line 19 and the ground line 15. Resistors 23 and 24 areconnected between the positive line 19 and the collectors of transistors17 and 25, respectively. The emitters of these transistors are connectedtogether and to the upper terminal of resistor 26, the lower terminal ofwhich is connected to the line 15 which is grounded to the chassis ofthe apparatus. The base of transistor 25 is connected to the collectorof transistor 17 through resistor 28 which is shunted by capacitor 29.Resistors 23, 27 and 28 are connected in series between the positiveline 19 and the ground line 15, and the common connection betweenresistors 27 and 28 is connected to the base of transistor 25 to providebias voltage thereto.

Each time a positive pulse is supplied to the base of transistor 17,that is, each time an article A passes between photodetector 10 andlight source 10a, a substantially square pulse is supplied to the baseof transistor 25. The cathode of diode 30 is connected to the collectorof transistor 25 and the anode of this diode is connected to the base oftransistor 22 so that a negative going square pulse is supplied to thebase of the latter transistor from the Schmitt trigger through diode 30when a positive pulse is developed in the circuit of photodetector 10.

The collector of transistor 31 is connected to the positive supply line19 and the base of this transistor is connected to the collector oftransistor 22. Thus, a negative going pulse is also supplied to line 32which is connected to the emitter of transistor 31. Line 32 transmitsthis negative going pulse to the differentiating circuit includingcapacitor 33 and resistor 34, and through capacitor 35 to the flip-flopgate employing transistors 36 and 37. Line 32 also supplies this pulseto the base of gating transistor 39 through capacitor 35 and resistor38. The flip-flop gate performs reset functions if abnormally longpulses are transmitted from the Schmitt trigger employing transistors 17and 25, as will be described hereinafter.

A unijunction transistor 40 is employed as a relaxation oscillator whichoperates continuously at a fixed frequency of about 1000 pulses persecond. The two connections of the unijunction transistor 40, which aremade to one portion of the semiconductor thereof, are connected throughresistors 41 and 42 to the positive supply line 19 and the ground line'15, respectively. Also, the lower semiconductor connection is connectedto the emitter of the gate transistor 39.

It will be noted that the collector of transistor 39 is connected to theground line 15 through resistors 43 and 44 and the common connectionbetween these resistors is connected to line 45 which is the counterinput line leading to the counter and driver unit 46 shown in FIG. 1.Thus, the collector of the gating transistor 39 is supplied withnegative potential.

The junction electrode of the unijunction transistor 40 is connected tothe upper terminal of capacitor 48 and through resistor 47 to thevariable resistor 47 which is used to control the frequency of thepulses generated by the unijunction relaxation oscillator. The variableresistor 47 is preferably positioned. outside of the logic unit, asshown in FIG. 1, so that it is readily accessible for adjusting thefrequency of the oscillator.

Transistor 39 functions as a gate for supplying pulses generated by therelaxation oscillator 40 to the line 45 and counter unit 46 while anarticle A is passing between photodetector 10 and light source 10a.Transistor 39 supplies these pulses to line 45 when a negative goingpulse is applied to the base thereof from transistor 31 by way of line32, coupling capacitor 35 and resistor 38. This negative going pulse isof course above the ground potential of line 15. Thus, pulses aresupplied from the relaxation oscillator 40 to the counter input line 45as long as the photodetector 10 is coveed by an article being scanned.

The negative going pulse on line 32 is also transmitted to thedifferentiating circuit, including the capacitor 33 and resistor 34,which is connected to the base of transistor 50. Diode 51 is connectedwith its cathode to the base of transistor 50 and its anode to theground line 15 to bypass the negative spike of the pulse resulting fromdifferentiation of the pulse supplied over line 32. The collector oftransistor 50 is connected to the positive line 19 and the emitter isconnected through resistor 52 to the reset signal line 53. Two branches55 and 56, shown in FIGS. 1 and 5, are provided to the reset signalline. Branch 55 is connected to counter unit 46 to reset the binarycounting unit 100 thereof and branch 56 is connected to counter unit 57to reset a similar binary counting unit therein. Another resistor 54 isconnected between line 53 and ground line 15.

The output of transistor 50 is connected as an emitter follower to thecathode of diode 62a. The anode of diode 62a is connected to line 58which is connected to the base of transistor 59. It will be noted thatresistors 52, 54 and 63 are connected in series between the positive 15volt line 19 and ground line 15. Line 58 is also connected to the anodeof diode 62, the cathode of which is connected to the collector oftransistor 91 and through resistor 64 to the collector of transistor 65of the flip-flop circuit, which will be described hereinafter.

Line 58 is also connected to the bottom terminal of resistor 63, the topterminal of which is connected to the positive line 19. Thus, transistor50 is actually connected across resistor 63 which is connected betweenthe positive 15 volt line and the base of transistor 59. The collectorof transistor 59 is also connected to the positive 15 volt line 19 andthe emitter of this transistor is connected to line 61 which forms theoutput circuit carrying the signal corresponding to the medium lengthproducts. Line 61 is connected to the counter and driver unit 46, asshown in FIG. 1, and supplies a signal to drive a Schmitt triggercircuit employed in this unit, as will be described hereinafter.

Two coincidence circuits employing transistors 66-67 and 68-69 areemployed in the logic unit of this apparatus shown in FIG. 5A. Thecollectors of these transistors are connected together to the positive 7volt supply line 70. Line 70 is connected through resistor 71, shown inFIG. 1, to the positive terminal of the bridge rectifier 72 which isconnected to the secondary 73 of transformer 74. Bridge rectifier 72also supplies current to the 15 volt line 19 through resistor 75.Resistors 71 and 75 function as voltage dropping resistors to reduce thevoltages on lines 19 and 70 to 15 volts and 7 volts, respectively.Suitable voltage regulating diodes 76 and 77 of the Zener type areconnected between lines 70 and 19, respectively, and ground line 15, andthese voltage regulating diodes are shunted by capacitors 78 and 79,respectively. Filter capacitor 80 is connected across the rectifierbridge circuit 72. Another bridge rectifier circuit 81 is connectedacross the secondary 82 and filter capacitor 83 is connected across thislatter bridge circuit. Bridge circuit 81 prO- vides positive 24 voltsupply to line 84 leading to the counter and driver units 46 and 57 andsolenoid valves 85 and 86, as shown in FIG. 1.

Transistors 87, 88 and 89, shown in FIG. 5A, are employed to provide aregulated 4 volt current supply to line 90 which is connected to theemitters of transistors 91 and 92 employed in the reset circuit. Thevoltage drop across transistor 87 is maintained at about 3 volts tomaintain the voltage of line 90 substantially constant at 4 volts. Thisline is provided with a filter capacitor 93 of large capacity.

Resistors 94 and 95 are connected in series between the 4 volt line 90and the ground line 15, and the common connection between theseresistors is connected to the base of the regulating transistor 89.Resistor 96 is connected between the 7 volt supply line 70 and the baseof transistor 88 and also the collector of transistor 89. The emitter oftransistor 89 is connected to the anode of diode 97. The cathode ofdiode 97 is connected to the anode of diode 98, the cathode of which isconnected to the ground line 15. Thus, transistor 89 is connected inseries with resistor 96 and diodes 97 and 98 between the 7 volt supplyline 70 and the ground line 15 so that it controls the bias supplied tothe base of transistor 88. The collector of transistor 88 is connectedto the 7 volt line 70 and the emitter of this transistor is connected tothe base of transistor 87. Thus, transistor 88 controls the biassupplied to the base of transistor 87. The bias of the base oftransistor 89 is responsive to voltage fluctuations of the 4 volt line90 so that these fluctuations are used to control the bias of base oftransistor 87 through transistor 88 whereby the voltage drop acrosstransistor 87 is maintained at about 3 volts.

The counter driver units 46 and 57 are connected in accordance with thediagrams shown in FIGS. 6 and 6A which will now be described in detail.The block 100 is a decade counter and employs four flip-flops. Thisdecade counter is of conventional construction and may be of the type CLL 958 manufactured by the Fairchild Semiconductor Division of FairchildCamera and Instrument Corporation. The decade counter 100 is providedwith an input terminal connected to the input line 45 leading to thecontrol logic unit 11. It is also provided with a reset terminalconnected to the reset line 55 which leads to the control logic unit 11.The decade counter 100 is also provided with a terminal that isconnected to the 4 volt line 90 which is also connected to the upperterminal of each of the resistors 101 to 105, inclusive. The lowerterminals of resistors 101 to 105, inclusive, are connected to thecollectors of transistors 106 to 110, inclusive, respectively, and tolines 111 to 115, inclusive, respectively.

Decade counter unit 100 is provided with a terminal 116 which isconnected to the ground line 15 and, in addition, this unit is providedwith four output terminals 117, 118, 119 and 129 which are connected tothe bases of transistors 106, 107, 108 and 109, respectively, throughresistors 121, 122, 123 and 124, respectively. Terminals 117, 118, 119and 120 of the decade counter provide binary signal output.

The collectors of transistors 106, 107, 108 and 109 are connected to anetwork of diodes 125 to 135, inclusive, for the purpose of providing adecade digital output on contacts 136 to 144 of switch 145, and contacts146 to 154 of switch 155 from the binary output of decade counter 100.For this purpose the cathode of diode 125 is connected to the collectorof transistor 106; the cathodes of diodes 126, 127 and 128 are connectedto the collector of transistor 107; the cathodes of diodes 129, 130 and131 are connected to the collector of transistor 108, and the cathodesof diodes 132, 133, 134, and 135 are connected to the collector oftransistor 109. In addition, the anodes of diodes 125 and 135 areconnected together and to the number 9 contacts 144 and 154; the anodesof diodes 128, 130 and 134 are connected together and to the number 7contacts 142 and 152. The anodes of diodes 127 and 129 are connectedtogether and to the number 6 contacts 141 and 151; the anodes of diodes126 and 133 are connected together and to the number 5 contacts 140 and150, and the anodes of diodes 131 and 132 are connected together and tothe number 3 contacts 138 and 148. The number 1 contacts 136-146, thenumber 2 contacts 137-447, the number 4 contacts 139149 and the number 8contacts 143-153 of the count selector switches are connected directlyto the collectors of transistors 109, 108, 107 and 106, respectively.The anodes of the various diodes in the diode network are also connectedto the positive/4 volt line through resistors 156 to 161, as shown.

The collectors of diodes 106, 107, 108 and 109 are connected by lines111, 112, 113 and 114, respectively, to the anodes of diodes 111a, 112a,113a and 114a, respectively, and the cathodes of these diodes areconnected to one side of resistors 111b, 112b, 113b and 114b,respectively. The other sides of these resistors are connected togetherto the base of transistor 110. Diodes 111a, 112a, 113a and 114m andresistors 111b, 112b, 1131) and 114b form :an OR gate so that transistor110 is on as long as any one of transistors 106, 107, 108 and 109 is on.The emitter of transistor 110 is connected to the ground line 15 and thecollector thereof is connected to line 115 which leads to the zerocontacts of switches 145 and 155. Line 115 also leads to thedifferentiating circuit including the capacitor and resistor 163.Resistor 163 is connected between line 115 and the ground line 15 andthe diode 164 is connected with its cathode to line 115 and its anode toline 15 so that the negative pulse of the differentiated signal isbypassed through this diode to ground. The positive pulse is suppliedover output line 115 to the input of the decade counter in unit 57 shownin FIG. 1. Transistor 110 is off when the tenth pulse is supplied todecade counter inasmuch as at that time all the transistors 106, 107,108 and 109 are off. When transistor is turned off a pulse istransmitted over line 115.

The counter and driver unit 57 is the same as the unit 46 illustrated inFIGS. 6 and 6A. The input line leading to unit 57 from unit 46 furnishesthe input to the decade counter in unit 57.

Switch 145, which is designated the long tenths switch, is connected toline 145, as shown in FIG. 1, and this line leads to the base oftransistor 69, as shown in FIG. 5A of the logic unit 11. Switch 155which is designated the medium tenths switch is connected to line 155awhich leads to the base of transistor 67 shown in FIG. 5A of the logiccircuit 11. The counter-driver unit 57 is also provided with countselector switches b and corresponding to switches 145 and 155 ofcounter-driver unit 46. Count selector switch 145b, which is connectedto the unit 57, is designated as the long units switch, and this switchis connected to line 145c leading to the base of transistor 68 of thelogic circuit shown in FIG. 5A. Count selector switch 15512 isdesignated as the medium units switch and this switch is connected toline 1550 leading to the base of transistor 66 in the logic circuitshown in FIG. 5A.

Switches 145b and 145 are adjusted to select the length of the longarticle in the sorting process. Thus, if switch 145b is set on contact 4and switch 145 is set on contact 5, then the apparatus is set to selectlong products having lengths of 4.5 units. These contacts must besupplied with pulses simultaneously from the counter-driver circuits 46and 57, respectively, so that both the transistors 68 and 69 are turnedon simultaneously. The emitters of these transistors are connectedthrough diodes 165 and 166 to the line 167 which is connected to thebase of transistor 168 through resistor 169. The collector of transistor168 is connected to line 170 which is referred to as the output linecarrying the signal for the long product. Line 170 leads from thecontrol logic unit 11 to the drive input of the unit 57, as shown inFIG. 1. This corresponds to the drive input line 61 on unit 46 shown inFIG. 6A.

Likewise, if the medium units switch 155b is positioned on contact 2thereof and the medium tenths switch 155 is positioned on contact 3, theapparatus is set for medium length products of 2.3 units. These contactsmust be activated simultaneously from the units 57 and 46, respectively,so that transistors 66 and 67 are turned on simultaneously. The emittersof these transistors are connected to cathodes of diodes 171 and 172,respectively, and the anodes of these diodes are connected together toline 173. Line 173 is coupled by capacitor 174 to the base of transistor175 which is connected as a flipflop oscillator with transistor 65, asshown in FIG. 5. Thus, for medium length products, a positive pulse issupplied on line 173 to the base of transistor 175 which is turned onthereby and transistor 65 of the flip-flop is turned off. Transistor 175also turns transistor 91 off and, as a result, the cathode of diode 62becomes more positive. Diodes 62 and 62a form an AND gate forcontrolling transistor 59 which is turned on when both of these diodesare high. The base of transistor 59 is supplied with pulses over line 58from diode 62a which are derived from the output of the Schmitt triggerthat is connected to the photodetector 10. Line 58 carries signalscorresponding to long, medium and short products A, A1 and A2 shown inFIG. 2. However, transistor 59 is turned on only when a positive signalis also transmitted over line 173 to the reset flip-flop. The emitterfollower of transistor 59 is connected to output line 61 which carriesthe signal for the medium length products to the multivibrator employingtransistors 179, 181 and 182 shown in FIG. 6A.

The signal supplied on line 61 which corresponds to the medium lengthproducts is fed to the ditferentiating circuit including the capacitor176 and resistor 177 shown in FIG. 6A. The positive pulse of thedifferentiated signal is passed through diode 178 to the base oftransistor 179. The negative pulse of this signal is bypassed throughdiode 180 to ground line 15. Transistors 179 and 181 are connected as aSchmitt trigger circuit which is provided with regenerative feedback bytransistor 182 so that the circuit becomes a monostable multivibratoradapted to generate pulses of predetermined length depending on thesetting of the variable contact on potentiometer 200. This potentiometeris referred to as the air delay and provides for the desired delaybefore the medium air valve 85 is turned on to deflect the product, aswill be described hereinafter.

Transistors 179 and 181 have the collectors thereof connected to the 15volt supply line 19 through resistors 183 and 184, respectively. Theemitters of these transistors are connected together and to the topterminal of resistor 185. The bottom terminal of this resistor isconnected to the ground line 15. Additional resistors 186 and 187 areconnected in series between the collector of transistor 179 and theground line 15 and the common connection of these resistors is connectedto the base of transistor 181. The collector of transistor 181 is alsoconnected to the upper terminal of the capacitor 188 and to the cathodeof diode 189. The anode of this diode is connected to the base oftransistor 190.

Capacitor 188 and resistor 200 form a time delay circuit to control thefeedback to the base of transistor 179 through transistor 182. Outputline 195 leading to the anode of diode 201 (FIG. A) from the delaycircuit supplies a reset pulse to the base of transistor 65 of theflip-flop (FIG. 5) to turn this transistor on and turn transistor 175off.

The anode of diode 201 is connected to line 195 and the cathode of thisdiode is connected to the upper terminal of resistor 201a and the righthand side of capacitor 20121. The left hand side of this capacitor isconnected to the upper terminal of resistor 201a and to the base oftransistor 65. The bottom terminals of resistors 201a and 201c areconnected to the ground line 15. Thus, a positive reset pulse issupplied over line 195 to the base of transistor 65 through diode 201and capacitor 201b. An additional diode 201d is connected with itscathode to 8 the upper terminal of its resistor 201a and with its anodeto line 167. Thus, a reset pulse may also be supplied to the base oftransistor 65 from the long signal pulse line 167.

The collector of transistor 190 is connected to the positive 15 voltline 19 through resistor 191 and it is also connected to one side of thecapacitor 193. Capacitor 193 and resistor 194 form a differentiatingcircuit which receives a relatively long pulse from the monostablemultivibrator employing transistors 179, 181 and 182 and differentiatesthis pulse so that a positive and a negative pulse are producedtherefrom. The negative pulse is bypassed to the ground line by diode197 which is connected across resistor 194, and the positive pulse isfed through diode 196 to line 198 which leads to the base of transistor199. Transistors 199, 205 and 206 comprise another monostablemultivibrator for controlling the time interval air is supplied to themedium product air valve a.

The collectors of transistors 199 and 205 are connected to the positive15 volt line 19 through resistors 207 and 208, respectively, and theemitters of these two transistors are connected together and to the topterminal of resistor 209, the bottom terminal of which is connected tothe ground line 15. The base of transistor 205 is connected to thecollector of transistor 199 and to the top terminal of resistor 210, thebottom terminal of which is connected to the ground line 15. Feedback tothe base of transistor 199 is supplied from the emitter of transistor206. The base of this transistor is connected to the variable contact ofpotentiometer 204.

Potentiometer 204 and capacitor 204a, which are connected in seriesbetween the collector of transistor 205 and ground line 15, form a delaycircuit. Thus, by adjusting the variable contact of the potentiometer204, the feedback in the monostable multivibrator is controlled and thelength of the pulse produced by this multivibrator may be adjusted.Potentiometers 200 and 204 and 200- 204 (FIG. 1) which are connected tothe monostable multivibrators in units 46 and 47 are provided for thepurpose of obtaining predetermined delay and timing of the energizationof the solenoids 85 and 86. The connections to potentiometers 200 and204 are shown in FIG. 6A and potentiometers 200 and 204' are connectedin similar fashion to monostable multivibrators provided in unit 57.Potentiometers 200 and 200 are adjusted to provide for air delay, thatis, to compensate for the time it takes for the product to travel fromthe scanning zone to the appropriate air jet nozzle. In other words, ifthe compressed air were turned on by valves controlled by the solenoids85 or 86 at the time that the product is being scanned for lengthdetermination, then, obviously, the air jet would be premature.Accordingly, the potentiometers 200 and 200' are adjusted to delay theapplication of the signal to the solenoids an appropriate length of timerequired for the product to travel from the scanning zone to the air jetzone. Potentiometers 204 and 204' are provided for controlling the airtime, that is, the time the air is turned on at the jets so that the airjet is turned on long enough to develop the proper product deflectingaction.

The output of the second monostable multivibrator comprising transistors199, 205 and 206 is supplied to the base of transistor 211 from thecollector of transistor 205 and is amplified by transistors 211, 214 and216. The collector of transistor 211 is connected to the 15 volt line 19and the emitter of this transistor is connected to the cathode of diode213, the anode of which is connected through resistor 212a to the baseof transistor 214. Also, the emitter of transistor 211 is connected tothe top terminal of resistor 212, the bottom terminal of which isconnected to the ground line 15. The collector of transistor 214 isconnected to the base of transistor 216 and also to the positive 24 voltline 84 through resistor 215. The emitter of transistor 214 and theemitter of transistor 216 are both connected to the ground line 15. Thecollector of transistor 216 is connected to line 218 which leads to thesolenoid 85' controlling the valve 85a through which air is supplied forthe air jets employed for deflecting the medium length products. The 24volt line 84 also is connected to the solenoid 85 and diode 217 isconnected between line 84 and line 218 to bypass thecounter-electromotive force generated in this solenoid when energizationthereof is interrupted, that is, when transistor 216 is turned off.

The monostable multivibrators employing the transistors 179, 181, 182and the transistors 199, 205, 206 are included in the unit 46 shown inFIG. 1 which is designated the tenths counter-medium driver, and theycomprise the medium length product driver. A similar arrangement ofmultivibrators is employed in the unit 57 which is designated the unitscounter-long driver and the output line 219, which is connected betweenthe unit 57 and the solenoid 86, corresponds to the output line 218connected between unit 46 and solenoid 85. Thus, when a signalcorresponding to a long product is supplied over long line 170 from thelogic unit 11 to the unit 57, an output signal is transmitted over line219 to the solenoid 86. This solenoid controls an air valve 86a whichsupplies compressed air to the air jet positioned at the outlet theconveyor 12, 13 to deflect the long product. Likewise, a signal from thetenths counter-medium driver unit 46 energizes solenoid 85 whichcontrols an air valve 85a which supplies compressed air to the air jetpositioned at the outlet of the conveyor 12, 13 to deflect the mediumproduct.

The flip-flop including transistors 36 and 37 is provided forcontrolling the transistor 39 in cases where an unusually long gatingaction prevails at this transistor. Under such conditions it is desiredto turn off this transistor even though a negative going signal is beingsupplied thereto over line 32, and this flip-flop is provided for thatpurpose. The emitters of the transistors 36 and 37 are connectedtogether to the ground line 15 and the collectors are connected to thepositive 15 volt line 19 through resistors 36d and 37d, respectively.Resistors and capacitors are provided between the bases of thesetransistors and the collectors thereof, as employed in conventionalflipflop circuits. In addition, the base of transistor 37 is connectedto the cathodes of diodes 36c and 37a. The anodes of diodes 36c and 37care connected to one side of the resistors 36b and 37b, respectively.The other sides of these resistors are connected to the ground line 15.Capacitor 36a is provided between the anode of diode 36c and line 61, asshown in FIG. A, and capacitor 37a is provided between the anode ofdiode 37c and line 181A in FIG. 6A. Capacitors 36m and 37a and resistors36b and 37b form circuits of suitable time constants so that thesuitable energizations thereof from either line 61 or line 181A willturn transistor 37 on and turn transistor 36 off. When transistor 36 ison, it does not interfere with the negative going signal being suppliedto the base of transistor 39. However, when transistor 37 is turned onand transistor 36 is turned off, then the base of transistor 39 becomesexcessively positive and this transistor is thus turned ofi even thoughthe negative going signal is being supplied thereto over line 32.

The operation of this apparatus is summarized as follows. A product A tobe graded according to length is passed by the conveyor 12, 13 into thescanning zone at a predetermined speed. When the product A is in thescanning zone it interrupts the light passing from the light source a tothe photodetector 10, thereby causing a positive pulse to be generatedby the Schmitt trigger employing transistors 17 and 25. The length ofthe positive pulse depends on the length of the product and the speed atwhich it is moved by the conveyor. A corresponding negative going pulseis supplied on the output line 32 of transistor 31 and this negativegoing pulse is transmitted to the differentiating circuit employingcapacitor 33 and resistor 34, from which the positive spike istransmitted to the base of transistor 50 which transmits a positivepulse to the base of transistor 59 over line 58. Line 32 also supplies anegative going pulse to the base of transistor 39 through capacitor 35and resistor 38'. Transistor 39 functions as a gate passing pulsesgenerated by the unijunction multivibrator employing transistor 40, aslong as the base thereof is receiving the negative going pulse andtransmitting these pulses to the output line 45, which is connected tothe decade counter in the unit 46. If the flip-flop employingtransistors 36 and 37 should be operated, as will be described laterhereinafter, to raise the potential of the base of transistor 39 to apredetermined positive potential, then transistor 39 will shut offpassage of the pulses from the unijunction multivibrator to line 45 eventhough a product is between the light source 10a and the photodetector10, since the negative going pulse supplied over line 32 is insuflicientto overcome the positive bias supplied from the flip-flop employingtransistors 36 and 37.

Line 45 supplies pulses to the decade counter 100 as long as the productA is passing between the light source 10a and the photodetector 10 so asto interrupt passage of light therebetween, Decade counter 100 providesbinary signal output to the bases of transistors 106, 107, 108 and 109over lines connected to output terminals 117, 118, 119 and 120,respectively. This signal output is illustrated in FIG. 7 in which thewaveforms on the input line 45 and the binary output terminals 117,118', 119 and 120 are illustrated opposite these reference numerals. Thediode network connected to these transistors decodes the binary outputinto a decade output which is supplied to the contacts of switches 145and 155, which are designated as the long tenths and medium tenthsswitches, respectively.

As long as the binary output signals from the counter 100 function toturn the transistors 106, 107, 108 and 109 on, transistor remains 06.This condition prevails during the first nine pulses supplied to counter100 over line 45. On the tenth pulse all transistors 106, 107 108 and109 are turned oflf and transistor 110 is turned on through theoperation of the OR circuit connected to the base thereof. A pulse isthen supplied to line and to the dilferentiating circuit includingcapacitor 162 and resistor 163. Line 115 is connected to the input ofthe decade counter in unit 57 which corresponds to the decade counter100 in unit 46, shown in FIG. 6, Thus, the counter in unit 57 receivesone pulse over line 115 for each ten pulses supplied to counter 100 inunit 46 over line 45. The circuit of unit 57 is similar to that in unit46. Unit 57 also includes a binary to decade decoder which is connectedto the contacts of the long units and medium units switches b and bshown in FIG. 1.

At the outset when this apparatus is adjusted for operation, the longunits switch 145b and the long tenths switch 145 are set onpredetermined contacts thereof which correspond to the selected lengthsof the long product. Thus, switch 1451: may be set on contact 4 andswitch 145 may be set on contact 5. This adjustment may be made tocorrespond substantially to 4.5 inches by adjusting the oscillatorfrequency by varying the potentiometer 47 or by adjusting the speed ofthe conveyors 12-13, or both. The medium units switch 155b and mediumtenths switch 155 are also set so that the apparatus will select themedium length products. For example, switch 155b may be set on contact 3and switch 155 may be set on contact 2, giving a medium product lengthof 3.2, which, of course, must be less than the long product lengthselected above.

In order for the apparatus to select a long product, both lines 145a and145:: must be energized simultaneously from the counters in apparatus 46and 57 so that signals are supplied simultaneously thereby to the basesof transistors 68 and 69, shown in FIG. 5A. These transistors form partof a coincidence circuit and the emitters thereof supply signals to thediodes 165 and 166 which supply a positive signal over line 167 to thebase of transistor 168. This transistor is connected to line 170 whichtransmits a signal to the long driver apparatus 57. At the 1 l sametime, a positive signal is supplied over line 167 to diode 201d whichtransmits this signal to the base of transistor 65 to reset theflip-flop employing transistors 65 and 175 so that transistor 65 isturned on in case it was turned off, and this blocks the AND gateemploying transistor 59.

Line 170 leads from the control logic unit 11 to the long drivermonostable multivibrators in the unit 57 which function as previouslydescribed to supply a signal on line 219 to the solenoid 86 whichcontrols the air jet valve 86a. Energizing the solenoid 86 opens thevalve 86a and provides a blast of air to deflect the long product A andcause it to travel to the long product conveyor or receptacle.

The signal corresponding to a medium length product is transmitted overlines 155 and 1550 to transistors 66 and 67 of the coincidence circuit,shown in FIG. 5A, and through these transistors to the diodes 171 and172. These diodes transmit the signal to line 173 which is connectedthrough capacitor 174 to the base of transistor 175 of the resetflip-flop which is turned on by this signal and transistor 65 is turnedoff. At the same time the cathode of diode 62 becomes more positivesince transistor 91 is turned off. It will be noted that diodes 62 and62a comprise an AND gate, and when positive potential is applied to thecathodes of both of these diodes, then transistor 59 is turned on andthe signal corresponding to the medium length product is supplied toline 61 which is connected to the medium driver circuit in unit 46. Themonostable multivibrators of this unit function to cause energization ofline 218 which leads to the solenoid 85. This solenoid opens the airvalve 85a and an air jet is supplied at a predetermined time to deflectthe medium length product A1. It will be noted that this apparatusprovides no means for deflecting the short length products, and theseare allowed to proceed without deflection to a suitable conveyor orreceptacle provided therefor while the long and medium products aredeflected to separate conveyors or receptacles.

While I have shown a preferred embodiment of the invention, it will beapparent to those skilled in the art that the invention is capable ofvariation and modification from the form shown.

What I claim is:

1. In apparatus for sorting products according to their lengths, thecombination comprising means moving the product to be sorted through azone having scanning means, said scanning means having means generatingan electric pulse when a product is in the process of being scanned,means responsive to said electric pulse transmitting an electric signalwhile the product is in said scanning zone, said signal comprising anumber of pulses determined by the length of the time interval that theproduct Was in said scanning zone, means responsive to said number ofpulses producing control signals characterized by two different productlengths, said last mentioned means including means selecting differentvalues for each of said different product lengths, means including agate responsive to said electric pulse and to the control signalcharacterized by one of said product lengths, said last mentioned meansincluding a flip-flop circuit which is responsive to the control signalcorresponding to said one product length and is set thereby, and meansactivated by the control signal corresponding to the other of saidproduct lengths resetting said fiipfiop circuit if said circuit waspreviously in set condition, means associated with said product movingmeans for separating said products according to said different lengthsand means responsive to said control signals activating said separatingmeans, said last mentioned means including said gate and said flip-flopcircuit.

2. In apparatus for sorting products according to their lengths, thecombination comprising means moving the product to be sorted through azone having scanning means, means transmitting an electric signal whilethe product is in said scanning zone, said signal comprising a number ofpulses determined by the length of time interval that the product is insaid scanning zone, means responsive to said pulses for producingcontrol signals characterized by different product lengths, meansresponsive to said control signals connected to said last mentionedmeans for controlling separating means which separates the productsaccording to their lengths, said separating means including solenoidvalves controlling air jets, and said means producing control signalsincluding monostable multivibrator means for producing pulses of longenough duration to open the selected solenoid valves and provide an airjet to deflect the predetermined products.

3. In apparatus for sorting products according to their lengths, thecombination as set forth in claim 2 further characterized in that saidmultivibrator means includes a cascade of two monostable multivibratorscontrolled by each of said control signals, the first thereof generatinga pulse which delays the opening of the predetermined solenoid valve for.a time interval required for the product to travel from the scanningzone to a zone opposite the air jet nozzle and the second multivibratorcontrolling the duration of energization of the predetermined solenoidvalve.

4. In apparatus for sorting products according to their lengths, thecombination comprising means moving the product to be sorted through ascanning zone, means producing an electric pulse while the product is insaid scanning zone, a pulse generator, pulse counting means, meansresponsive to said electric pulse for transmitting pulses from saidgenerator to said counting means during the time interval the product isin said scanning zone, means responsive to said counting means forproducing control signals characterized by medium and long productlengths, means associated with said counting means for selecting a rangeof different values for the medium and long product lengths, separatingmeans connected to said selecting means for separating the products inthe range of the desired lengths, a flip-flop circuit adapted to be setby the control signal corresponding to the medium product length, a gateresponsive to said electric pulse and to Said flip-flop circuit in theset condition for activating said separating means, and means activatedby the control signal corresponding to the long product length forresetting said flip-flop circuit if said flip-flop circuit waspreviously set by a control signal corresponding to said medium productlength.

5. In apparatus for sorting products according to their lengths, thecombination comprising means moving the product to be sorted through ascanning zone, means generating an electric signal while the product isin said scanning zone, a pulse generator, pulse counting means, meansresponsive to said electric signal for transmitting pulses to saidcounting means from said pulse generator during the time interval theproduct is in said scanning zone, means responsive to said countingmeans for producing control signals characterized by different productlengths, means selecting the control signals corresponding to thedesired product lengths, and means connected to said selecting means forseparating the products in the range of the desired lengths, includingsolenoid valves controlling air jets, and said means producing controlsignals including monostable multivibrator means for producing pulses oflong enough duration to open the selected solenoid valves and provide anair jet to deflect the predetermined products.

6. In apparatus for sorting products according to their lengths, thecombination as set forth in claim 5 further characterized in that saidmultivibrator means includes a cascade of two monostable multivibratorscontrolled by each of said control signals, the first thereof generatinga pulse which delays the opening of the predetermined solenoid valve fora time interval required for the product to travel from the scanningzone to a zone opposite the air jet nozzle and the second multivibratorcontrolling 13 the duration of energization of the predeterminedsolenoid valve.

7. In apparatus for sorting products according to their lengths, thecombination comprising means moving the product to be sorted through azone having scanning means, said scanning means comprising a lightsensitive device that is sensitive to infrared light connected to aSchmitt trigger circuit, means transmitting an electric signal while theproduct is in said scanning zone, said signal comprising a number ofpulses determined by the length of time interval that the product is insaid scanning zone, means selecting predetermined numbers of said pulsescorresponding to difierent product lengths, said last mentioned meansproducing control signals characterized by different product lengths,means connected to said last mentioned means for controlling separatingmeans which separates the products scanned according to their lengths.

8. In apparatus for sorting products according to their lengths, thecombination as set forth in claim 7 further characterized in that saidsignal transmitting means comprises a transistor and the output of saidSchmidt trigger is supplied in the form of a negative going pulse to thebase of said transistor.

9. The method of sorting products according to their lengths comprisingthe steps of moving a single file of the products oriented lengthwisethrough a scanning zone, generating an electric pulse while one of theproducts is being moved through the scanning zone, generating electricpulses continuously at a selected frequency, using said electric pulsefor controlling the transmission of said electric pulses to a pulsecounting apparatus, adjusting said counting apparatusfto produce controlsignals characterized by at least two diiferent product lengths,selectively transmitting said control signals to product separatingapparatus that is encountered by the products after the products passthrough said scanning zone, delaying the energization of the separatingapparatus by the control signal by the time interval required for theproduct to pass from the scanning zone to the separating apparatus,thereafter deflecting the product according to its length by directingan air jet thereagainst, and extending the time interval of the controlsignal sufiiciently to enable the air jet to deflect the product andeffect the separation thereof.

References Cited UNITED STATES PATENTS 9/1961 Gerhardt 20982 9/1966Allen 20974 US. Cl. X.R.

209-lll.7; 250223

